*Excludes Observations that spanned multiple years

Pre 19701
19700
19710
19720
19730
19740
19750
19760
19771
19780
19790
19800
19810
19820
19830
19840
19850
19860
19870
19882
19896
19900
199110
199212
19931
19940
199516
19961
19973
19981
19991
20001
20012
20021
20030
200411
20055
20060
20072
200812
20090
20100
20110
20120
20130
20140
20150
201611
20170
Total100